Marijuana is the most widely used illicit drug, with over 21 million individuals estimated to have used marijuana in the past year in 2001. Although prevalence rates for the general population have been relatively stable over the past 10 years, prevalence rates among youth rose considerably during the mid-1990s while perceptions of harm declined. With this rise in use has come a significant rise in arrests. There is increasing pressure on many state legislatures to soften their current policies toward marijuana as a way of reducing the criminal justice burden, following the example of Canada, Australia, Great Britain and several other European Countries. The problem is that these decisions are being considered in the absence of relevant information on the economic cost of marijuana use, abuse and dependence. This application is a competing continuation application for a current study entitled "Are there Economic Costs Associated with Marijuana Use?" (NIDA Grant #R01 DA12724). The previous study took some important first steps in exploring the relationship between marijuana use and some specific behaviors that could potentially impose costs on society. The goal of this new three-year project is to build on our previous work and provide additional estimates of the incremental costs associated with marijuana use as they pertain to three specific areas: (1) the cost of treating dependent and abusive users in hospital settings, (b) the costs associated with marijuana-involved accidents, and (c) the costs associated with crime. Information will be gathered from a variety of sources, including the National Inpatient Survey, the National Hospital Ambulatory Medical Care Survey, the Drug Abuse Warning Network, the General Estimates System, and Uniform Crime Reports to produce lower and upper bound estimates of the social costs of marijuana use in these areas. Although we recognize that other costs and benefits of marijuana use exist, we feel it is appropriate to limit the scope of this proposal so that in-depth and careful analyses can be done on these three topics as we believe that adequate data are finally available to generate reasonable first estimates of the costs in these areas.